questions stringlengths 37 1.22k | reasoning stringlengths 0 3.56k ⌀ | answers stringlengths 4 138 |
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Why do waves travel faster through solids?
Here are the choices:
A. particles range together
B. particles closer together
C. particles fuse together
D. particles pipe together | The speed of most waves depends on the medium, or the matter through which the waves are traveling. Generally, waves travel fastest through solids and slowest through gases. That’s because particles are closest together in solids and farthest apart in gases. When particles are farther apart, it takes longer for the ene... | B: particles closer together. |
What is the point on the ground that is located directly above where underground rocks fracture (or the "focus" point)?
Here are the choices:
A. danger zone
B. seismic point
C. epicenter
D. fault line | The focus is where the rocks rupture. The epicenter is the point on the ground directly above the focus. | C: epicenter. |
When atoms gain or lose electrons, they can form electrically charged particles called what?
Here are the choices:
A. eons
B. crystals
C. ions
D. toxins | In ordinary chemical reactions, the nucleus of each atom (and thus the identity of the element) remains unchanged. Electrons, however, can be added to atoms by transfer from other atoms, lost by transfer to other atoms, or shared with other atoms. The transfer and sharing of electrons among atoms govern the chemistry o... | C: ions. |
What do you call a pure substance that cannot be broken down into different types of substances?
Here are the choices:
A. molecule
B. element
C. sample
D. compound | An element is a pure substance that cannot be broken down into different types of substances. There are almost 120 known elements ( Figure below ), each with its own personality. The chemical and physical properties of one element differ from any other. Elements are arranged according to their properties in the Periodi... | B: element. |
Natural selection can only take place if there is variation, or differences, among individuals in a population. importantly, these differences must have some genetic basis; otherwise, the selection will not lead to change in this?
Here are the choices:
A. fertilization
B. spontaneous mutation
C. mass extinction
D. next... | Processes and Patterns of Evolution Natural selection can only take place if there is variation, or differences, among individuals in a population. Importantly, these differences must have some genetic basis; otherwise, the selection will not lead to change in the next generation. This is critical because variation amo... | D: next generation. |
The large hadron collider is the biggest type of what invention, which boosts particles to high energies?
Here are the choices:
A. particle accelerator
B. nuclear reactor
C. electron microscope
D. mass spectrometer | Chemistry in Everyday Life CERN Particle Accelerator Located near Geneva, the CERN (“Conseil Européen pour la Recherche Nucléaire,” or European Council for Nuclear Research) Laboratory is the world’s premier center for the investigations of the fundamental particles that make up matter. It contains the 27-kilometer (17... | A: particle accelerator. |
Metals, metalloids, and nonmetals are the different classes of what?
Here are the choices:
A. elements
B. structures
C. ions
D. compounds | The classes of elements are metals, metalloids, and nonmetals. They are color-coded in the table. Blue stands for metals, orange for metalloids, and green for nonmetals. You can read about each of these three classes of elements later in the chapter, in the lesson "Classes of Elements. ". | A: elements. |
What holds homologs together as the spindle forms for the first meiotic division?
Here are the choices:
A. magnetism
B. spirogyra
C. chiasmata
D. pollenation | C: chiasmata. | |
In the periodic table, elements are arranged from left to right according to what property?
Here are the choices:
A. atomic mass
B. metallic mass
C. real mass
D. major mass | You can see how Mendeleev organized the elements in Figure below . From left to right across each row, elements are arranged by increasing atomic mass. Mendeleev discovered that if he placed eight elements in each row and then continued on to the next row, the columns of the table would contain elements with similar pr... | A: atomic mass. |
What is made of gases that are essential for photosynthesis and other life activities?
Here are the choices:
A. stratosphere
B. air
C. atmosphere
D. ocean | The atmosphere is made of gases that are essential for photosynthesis and other life activities. | C: atmosphere. |
When a stream flows from a hard to soft rock area, what is often formed?
Here are the choices:
A. a riverbank
B. a river
C. a lake
D. a waterfall | Mountain streams may erode waterfalls. As shown in Figure below , a waterfall forms where a stream flows from an area of harder to softer rock. The water erodes the softer rock faster than the harder rock. This causes the stream bed to drop down, like a step, creating a waterfall. As erosion continues, the waterfall gr... | D: a waterfall. |
What term means taking used items and materials and turning them into something new?
Here are the choices:
A. collecting
B. recycling
C. reproducing
D. feeding | recycling: Takes used items and materials and turns it into something new. For example, 98% of car batteries are recycled today. In the processing plant, the plastic materials are separated from the lead, so the plastic can then be used for many applications. | B: recycling. |
What lets different species of anole lizards live in the same area without competing?
Here are the choices:
A. variation
B. concentration
C. specialization
D. cooperation | Specialization in Anole Lizards. Specialization lets different species of anole lizards live in the same area without competing. | C: specialization. |
What are made in the first step of the scientific method?
Here are the choices:
A. hypothesis
B. conclusions
C. observations
D. patterns | Scientific investigations generally follow a process called the scientific method. Steps of the scientific method include making observations, asking a question, forming a hypothesis, testing the hypothesis, drawing a conclusion, and communicating the results. | C: observations. |
What type of organisms do not need blood?
Here are the choices:
A. single-celled
B. cold-blooded
C. vertebrate
D. marine | Single-celled organisms do not need blood. They obtain nutrients directly from and excrete wastes directly into their environment. The human organism cannot do that. Our large, complex bodies need blood to deliver nutrients to and remove wastes from our trillions of cells. The heart pumps blood throughout the body in a... | A: single-celled. |
What type of plants are the mosses, the hornwarts, and the liverworts considered to be?
Here are the choices:
A. xerophyte
B. Vascular
C. spirogyra
D. nonvascular | Nonvascular plants include the mosses, the hornworts, and the liverworts. | D: nonvascular. |
Wearing what will reduce the amplitude of sound waves entering the ears?
Here are the choices:
A. megaphone
B. hearing protectors
C. goggles
D. hardhat | Hearing loss due to loud sounds can be prevented by wearing hearing protectors. They reduce the amplitude of sound waves entering the ears. | B: hearing protectors. |
What type of motion only occurs when there is one force applied at the beginning of the trajectory after which there is no interference apart from gravity?
Here are the choices:
A. projectile
B. thrust
C. velocity
D. propellant | projectile motion: A form of motion where a particle (called a projectile) is thrown obliquely near the earth's surface, & it moves along a curved path under the action of gravity. The path followed by a projectile motion is called its trajectory. Projectile motion only occurs when there is one force applied at the beg... | A: projectile. |
What type of energy is produced when two objects move together?
Here are the choices:
A. mechanical energy
B. potential energy
C. physical energy
D. molecular energy | A: mechanical energy. | |
Which form of matter assumes the shape of its container?
Here are the choices:
A. liquids
B. gas
C. crystals
D. solids | Gases assume the shape of their container. | B: gas. |
What type of energy is possessed by autumn leaves before they fall?
Here are the choices:
A. kinetic energy
B. mechanical energy
C. potential energy
D. radioactive energy | Before leaves fall from trees in autumn, they have potential energy. Why do they have the potential to fall?. | C: potential energy. |
The heterotroph eats only or mainly what?
Here are the choices:
A. plants
B. decomposers
C. roots
D. animals | heterotroph that eats only or mainly plants. | A: plants. |
All carbon atoms have how many protons?
Here are the choices:
A. six
B. eight
C. one
D. two | All carbon atoms have six protons. Most also have six neutrons, but some have seven or eight neutrons. What is the mass number of a carbon isotope that has seven neutrons?. | A: six. |
The cerebellum is associated with what major human organ?
Here are the choices:
A. liver
B. brain
C. heart
D. bladder | Figure 13.13 The Cerebellum The cerebellum is situated on the posterior surface of the brain stem. Descending input from the cerebellum enters through the large white matter structure of the pons. Ascending input from the periphery and spinal cord enters through the fibers of the inferior olive. Output goes to the midb... | B: brain. |
The kinetic energy of a moving object depends on it's mass and it's what?
Here are the choices:
A. shape
B. iron content
C. liquid content
D. volume | The kinetic energy of a moving object depends on its mass and its volume. | D: volume. |
Electromagnetic waves are comprised of what two types of energy?
Here are the choices:
A. electric and magnetic
B. magnetic and gravitational
C. solar and kinetic
D. kinetic and electric | Gamma rays are electromagnetic waves. Electromagnetic waves are waves of electric and magnetic energy that travel through space at the speed of light. The energy travels in tiny “packets” of energy, called photons. Photons of gamma energy are called gamma particles. Other electromagnetic waves include microwaves, light... | A: electric and magnetic. |
Cranial nerves convey specific sensory information from the head and neck directly to what organ?
Here are the choices:
A. eye
B. brain
C. heart
D. nose | Cranial Nerves Cranial nerves convey specific sensory information from the head and neck directly to the brain. For sensations below the neck, the right side of the body is connected to the left side of the brain and the left side of the body to the right side of the brain. Whereas spinal information is contralateral, ... | B: brain. |
Where are the viral enzyme and genome packaged inside?
Here are the choices:
A. ribosomes
B. mitochondria
C. pollen grains
D. viral capsid | D: viral capsid. | |
What would cause warm receptors to signal the hypothalamic thermostat?
Here are the choices:
A. lower temperature
B. hyperventilation
C. increased temperature
D. hypothermia | C: increased temperature. | |
The direction of the force of gravity is in what direction?
Here are the choices:
A. fragmented line
B. curved line
C. straight line
D. staggered line | The direction of the force of gravity is in a straight line between two objects. It is always attractive. | C: straight line. |
Sickle-cell anemia, leukemia, lymphoma, and hemophilia are examples of what types of disease?
Here are the choices:
A. Cancer
B. microscopic disease
C. Bone Diease
D. blood disease | Blood diseases include sickle-cell anemia, leukemia, lymphoma, and hemophilia. | D: blood disease. |
In hypothesis-based science, specific results are predicted from a general premise, which is called what type of reasoning that proceeds from general to particular?
Here are the choices:
A. reactive
B. deductive
C. transitive
D. reflexive | lecture. One observation to explain this occurrence might be, “When I eat breakfast before class, I am better able to pay attention. ” The student could then design an experiment with a control to test this hypothesis. In hypothesis-based science, specific results are predicted from a general premise. This type of reas... | B: deductive. |
The process by which an organism develops from a single-celled zygote to a multi-cellular organism is complex and well regulated. the regulation occurs through signaling between cells and tissues and responses in the form of what?
Here are the choices:
A. differential gene expression
B. spontaneous mutation
C. phenotyp... | The process by which an organism develops from a single-celled zygote to a multi-cellular organism is complex and well regulated. The regulation occurs through signaling between cells and tissues and responses in the form of differential gene expression. | A: differential gene expression. |
The development of specific structures in specific locations is called what?
Here are the choices:
A. pattern formation
B. specialty skills
C. adaptation
D. speciation | A: pattern formation. | |
An experiment generates what to support a hypothesis?
Here are the choices:
A. reason
B. study
C. falsehoods
D. evidence | A field goal kicker lines up to kick a 44 yard (40 m) field goal. He kicks it with an initial velocity of 22 m/s at an angle of . The field goal posts are 3 meters high. Does he make the field goal?. | D: evidence. |
What is the outermost occupied shell of electrons in an atom.
Here are the choices:
A. Inner Shell
B. valence shell
C. radiative shell
D. modular shell | The valence shell is the outermost occupied shell of electrons in an atom. This shell holds the valence electrons, which are the electrons that are involved in bonding and shown in a Lewis structure. Valence-shell electron pair repulsion theory , or VSEPR theory, states that a molecule will adjust its shape so that the... | B: valence shell. |
What ear structure has three fluid filled ducts, including the organ of corti, where sound waves in air go to vibration?
Here are the choices:
A. cochlea
B. utricle
C. semicirciular canal
D. saccule | Sensory systems deformed by gelatinous membrane. Vestibular apparatus, gives us perception of gravity and movement. Due to physical response, not chemical binding. Cochlea: bony, coil shaped part of inner ear, where hearing occurs. Sound enters through auditory canal, vibrates tympanic membrane,moving three bones of mi... | A: cochlea. |
What is the name for elements that neither contain carbon nor come from living things?
Here are the choices:
A. contaminants
B. minerals
C. acids
D. pigments | Minerals are chemical elements that don’t come from living things or include the element carbon. Many minerals are needed in the diet for normal functioning of the body. Several minerals that are needed in relatively large amounts are listed in Table below . As you can see from these examples, minerals have a diversity... | B: minerals. |
Kinetic energy is energy of this?
Here are the choices:
A. food
B. motion
C. speed
D. gravity | Kinetic Energy and the Ultimate Speed Limit Kinetic energy is energy of motion. Classically, kinetic energy has the familiar expression. | B: motion. |
Reproduction in prokaryotic cells is by what process of growth, enlargement and division?
Here are the choices:
A. mitosis
B. photosynthesis
C. binary fission
D. budding | Reproduction in prokaryotic cells is by binary fission ; a process of growth, enlargement and division. This will be discussed in the Cell Division: Prokaryotic (Advanced) concept. | C: binary fission. |
Why do some dry fruits split open at maturity?
Here are the choices:
A. to release toxins
B. to release berries
C. to release seeds
D. to regenerate | C: to release seeds. | |
What is an ionic bond in nature?
Here are the choices:
A. magnetic
B. electrostatic
C. radioactive
D. kinetic | An ionic bond is electrostatic in nature. | B: electrostatic. |
Most air masses form over what two types of regions?
Here are the choices:
A. arctic and marine
B. polar and arctic
C. polar and tropical
D. marine and tropical | Most air masses form over polar or tropical regions. They may form over continents or oceans. Air masses are moist if they form over oceans. They are dry if they form over continents. Air masses that form over oceans are called maritime air masses. Those that form over continents are called continental air masses. Figu... | C: polar and tropical. |
Earthworms are important deposit feeders that help form and enrich what material?
Here are the choices:
A. shale
B. coal
C. soil
D. wood | Earthworms are important deposit feeders that help form and enrich soil. | C: soil. |
Growth, morphogenesis, and cell differentiation produce the plant what?
Here are the choices:
A. fat
B. body
C. tail
D. fur | 35.5 Growth, morphogenesis, and cell differentiation produce the plant body. | B: body. |
What is a fold of the outer skin lining the shell called?
Here are the choices:
A. stack
B. mantle
C. cortex
D. marble | A mantle , or fold of the outer skin lining the shell. The mantle often releases calcium carbonate, which creates an external shell, just like the ones you find on the beach. The shell is made of chitin , a tough, semitransparent substance. | B: mantle. |
What sciences are the study of living organisms?
Here are the choices:
A. life sciences
B. physical sciences
C. social sciences
D. earth sciences | The life sciences are the study of living organisms. They deal with every aspect of living organisms, from the biology of cells , to the biology of individual organisms, to how these organisms interact with other organisms and their environment. | A: life sciences. |
Frogs are amphibians that live part of the time in fresh water and rest of the time where?
Here are the choices:
A. underground
B. in salt water
C. on land
D. in stagnant water | Amphibians are vertebrates that live part of the time in fresh water and part of the time on land. They were the first vertebrates to evolve four legs and colonize the land. They most likely evolved from lobe-finned fish. Modern amphibians include frogs, toads, salamanders, newts, and caecilians. They are ectotherms, s... | C: on land. |
Name the missing type of friction: static, rolling, fluid _____?
Here are the choices:
A. sliding
B. turning
C. dragging
D. falling | Friction is the force that opposes motion between any surfaces that are in contact. There are four types of friction: static, sliding, rolling, and fluid friction. | A: sliding. |
What is the study of how living organisms interact with each other and with their environment?
Here are the choices:
A. genetics
B. ecology
C. botany
D. zoology | Recall that ecology is the study of how living organisms interact with each other and with their environment. But how do organisms interact with each other? Organisms interact with each other through various mechanisms, one of which is competition. Competition occurs when organisms strive for limited resources. Competi... | B: ecology. |
What are electrons lost during the formation of ions called?
Here are the choices:
A. isotopes
B. cations
C. oxides
D. catalysts | Some elements lose one or more electrons in forming ions. These ions are known as “ cations ” because they are positively charged and migrate toward the negative electrode ( cathode ) in an electrical field. Looking at the periodic table below, we know that the group 1 elements are all characterized by having one s ele... | B: cations. |
Making a specific statement based on a general principle is the definition of what type of reasoning?
Here are the choices:
A. transitive
B. deductive
C. inference
D. inductive | Deductive reasoning means making a specific statement based on a general principle. | B: deductive. |
The earth's magnetic poles have done what repeatedly in the past?
Here are the choices:
A. rotated
B. demagnetized
C. switched places
D. stayed the same | Earth’s magnetic poles have switched places repeatedly in the past. As you can see in the Figure below , each time the switch occurred, Earth’s magnetic field was reversed. The magnetic field is the region around a magnet over which it exerts magnetic force. We think of today’s magnetic field direction as “normal,” but... | C: switched places. |
What do we call the orderly sequence of events in the life of a cell from the division of a single parent cell to produce two new daughter cells, to the subsequent division of those daughter cells?
Here are the choices:
A. cell cycle
B. cell death
C. cell replication
D. circadian cycle | 6.1 | The Genome By the end of this section, you will be able to: • Describe the prokaryotic and eukaryotic genome • Distinguish between chromosomes, genes, and traits The continuity of life from one cell to another has its foundation in the reproduction of cells by way of the cell cycle. The cell cycle is an orderly s... | A: cell cycle. |
What are natural resources which can be replaced in a relatively short period called?
Here are the choices:
A. materials resources
B. renewable resources
C. replaceable resources
D. solvent resources | Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply. Renewable energy resources include sunlight, moving water, wind, biomass, and geothermal energy. Each of these energy resources is described in Table below . Resources such as sunlig... | B: renewable resources. |
The biological electron transport chain provides for an orderly, stepwise transfer of electrons. both nadh (reduced nicotinamide adenine dinucleotide) and fadh2 (reduced flavin adenine dinucleotide) are energy rich molecules that liberate a large amount of energy during what?
Here are the choices:
A. extrapolation
B. o... | The biological electron transport chain provides for an orderly, stepwise transfer of electrons. Both NADH (reduced nicotinamide adenine dinucleotide) and FADH2 (reduced flavin adenine dinucleotide) are energyrich molecules that liberate a large amount of energy during oxidation. Free energy released during the transfe... | B: oxidation. |
The cells within meristems divide relatively frequently, generating additional what?
Here are the choices:
A. photosynthesis
B. proteins
C. cells
D. chlorophyll | C: cells. | |
Another unit of energy, used widely in the health professions and everyday life, is _______?
Here are the choices:
A. biomass ( cal )
B. carbs
C. body index
D. calorie ( cal ) | example, if you hold an ice cube in your hand, the ice cube slowly melts as energy in the form of heat is transferred from your hand to the ice. As your hand loses energy, it starts to feel cold. Because of their interrelationships, energy, work, and heat have the same units. The SI unit of energy, work, and heat is th... | D: calorie ( cal ). |
What are the specfic types of proteins that determine your blood type called?
Here are the choices:
A. Plasma
B. antigens
C. antibodies
D. Globulins | Red blood cells carry proteins called antigens on their surface. People may vary in the exact antigens their red blood cells carry. The specific proteins are controlled by the genes they inherit from their parents. The particular antigens you inherit determine your blood type. | B: antigens. |
Which layer of soil experiences the most weathering?
Here are the choices:
A. top layer
B. subsoil
C. bedrock
D. humus | Soil develops over time and forms soil horizons. Soil horizons are different layers of soil with depth. The most weathering occurs in the top layer. This layer is most exposed to weather! It is where fresh water comes into contact with the soil. Each layer lower is weathered just a little bit less than the layer above.... | A: top layer. |
Osteoporosis, osteoarthritis, fractures, and sprains are problems affecting what system?
Here are the choices:
A. nervous system
B. tissues system
C. digestive system
D. skeletal system | Possible problems of the skeletal system include osteoporosis, osteoarthritis, fractures, and sprains. | D: skeletal system. |
What are typically arranged into complex tubular networks with extensive surface areas?
Here are the choices:
A. transport epithelia
B. alveoli
C. Golgi apparatus
D. hair follicles | A: transport epithelia. | |
What is the simplest unit of structure and function of all living organisms called?
Here are the choices:
A. atom
B. cell
C. molecule
D. partical | A cell is the simplest unit of structure and function of all living organisms. From the smallest bacteria to the largest whale, all life is made of at least one cell. | B: cell. |
Activities that can reduce the effects of what condition include exercises to keep the blood and lymph flowing through affected areas?
Here are the choices:
A. asthma
B. anemia
C. inflammation
D. edema | Medications that can result in edema include vasodilators, calcium channel blockers used to treat hypertension, nonsteroidal anti-inflammatory drugs, estrogen therapies, and some diabetes medications. Underlying medical conditions that can contribute to edema include congestive heart failure, kidney damage and kidney d... | D: edema. |
An alloy is a mixture of metals that has bulk metallic properties different from those of its what?
Here are the choices:
A. mineral elements
B. system elements
C. nuclear elements
D. constituent elements | atoms held together by covalent bonds; they tend to be very hard and have high melting points. Metallic solids have unusual properties: in addition to having high thermal and electrical conductivity and being malleable and ductile, they exhibit luster, a shiny surface that reflects light. An alloy is a mixture of metal... | D: constituent elements. |
There are two types of digestion, mechanical and what else?
Here are the choices:
A. mineral
B. chemical
C. radiation
D. thermal | Digestion consists of mechanical and chemical digestion. | B: chemical. |
What is the rate at which energy is being transferred called?
Here are the choices:
A. power
B. force
C. pressure
D. electric | Power is the rate at which energy is being transferred. Power tells you how many Joules per second of energy is being used to drive something. Thus power is simply the change in energy divided by the time. Since work is by definition the transfer of energy (in or out of a system), power is also equal to the work divide... | A: power. |
Where does the process of assembling amino acids into a protein take place?
Here are the choices:
A. in chromosomes
B. in the ribosome
C. in the nucleus
D. in the chitin | The process of assembling amino acids into a protein takes place in the ribosome. This structure consists of two subunits, each of which is composed of both proteins and ribosomal RNA (rRNA). The two subunits clamp together on the mRNA and catalyze the formation of the amide linkages in the growing protein. When protei... | B: in the ribosome. |
Where can you find sodium acetate?
Here are the choices:
A. baking soda
B. a cold pack
C. a heat pack
D. table salt | In the picture above, a thermal pack is applied to the back. Small packs can be used either for heating or cooling, depending on the material used. A heat pack contains a supersaturated solution of material such as sodium acetate. The solution is clear until a small metal trigger is activated. The sodium acetate then c... | C: a heat pack. |
For a given amount of solute, do smaller particles have a greater or lesser surface area?
Here are the choices:
A. equal
B. neither
C. lesser
D. greater | A third factor that affects the rate of dissolving is the size of solute particles. For a given amount of solute, smaller particles have greater surface area. With greater surface area, there can be more contact between particles of solute and solvent. For example, if you put granulated sugar in a glass of iced tea, it... | D: greater. |
What is the functional unit of compact bone?
Here are the choices:
A. the auteron
B. the boron
C. the osteon
D. the canton | Bone matrix provides bones with their basic structure. Notice the spongy bone in the middle, and the compact bone towards the outer region. The osteon is the functional unit of compact bone. | C: the osteon. |
Mineralocorticoids are hormones synthesized by the adrenal cortex that affect what balance, by regulating sodium and water levels?
Here are the choices:
A. homeostasis
B. blood pressure
C. equilibrium
D. osmotic | Mineralocorticoids Mineralocorticoids are hormones synthesized by the adrenal cortex that affect osmotic balance. Aldosterone is a mineralocorticoid that regulates sodium levels in the blood. Almost all of the sodium in the blood is reclaimed by the renal tubules under the influence of aldosterone. Because sodium is al... | D: osmotic. |
The pulmonary circulation carries blood between what two organs?
Here are the choices:
A. kidney and heart
B. heart and pancreas
C. heart and lungs
D. lungs and kidney | The pulmonary circulation carries blood between the heart and lungs. The systemic circulation carries blood between the heart and body. | C: heart and lungs. |
The ancient greek philosopher aristotle thought that all matter consists of just four what, which he identified as earth, air, water, and fire?
Here are the choices:
A. elements
B. ingredients
C. structures
D. compounds | The idea of elements is not new. It dates back about 2500 years to ancient Greece. The ancient Greek philosopher Aristotle thought that all matter consists of just four elements. He identified the elements as earth, air, water, and fire. He thought that different kinds of matter contain only these four elements but in ... | A: elements. |
What are archaea that live in extremely hot environments called?
Here are the choices:
A. thermophiles
B. tardigrades
C. hypothermic
D. hemophiliacs | Archaea that live in extremely hot environments are called thermophiles. | A: thermophiles. |
Warming conditions and, perhaps, human activities contributed to what fate of many organisms of the pleistocene era?
Here are the choices:
A. evolution
B. accumulation
C. extinction
D. overpopulation | Many of the organisms that made up the Pleistocene megafauna went extinct as conditions warmed. Some may have been driven to extinction by human activities. | C: extinction. |
Practical limits of van de graaff generators arise because the large electric fields polarize and eventually do what to surrounding materials?
Here are the choices:
A. ionize
B. isolate
C. displace
D. decompose | The Van de Graaff Generator Van de Graaff generators (or Van de Graaffs) are not only spectacular devices used to demonstrate high voltage due to static electricity—they are also used for serious research. The first was built by Robert Van de Graaff in 1931 (based on original suggestions by Lord Kelvin) for use in nucl... | A: ionize. |
The remainder is transferred by contraction of what before the ventricles begin to contract?
Here are the choices:
A. the arteries
B. the stomach
C. the large intestine
D. the atria | D: the atria. | |
Chromatin condenses into chromosomes during prophase, the first and longest phase of what process?
Here are the choices:
A. apoptosis
B. reproduction
C. mitosis
D. meiosis | The first and longest phase of mitosis is prophase . During prophase, chromatin condenses into chromosomes, and the nuclear envelope, or membrane, breaks down. In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles of the cell. As the centrioles move, a spindle starts to form betw... | C: mitosis. |
What do plants lose the most of through the stomata?
Here are the choices:
A. water
B. chlorophyll
C. energy
D. heat | A: water. | |
Unburned hydrocarbons can more easily be converted to carbon dioxide and water in the presence of a what?
Here are the choices:
A. catalyst
B. Ethanol
C. temperature
D. methane | Catalytic converters in cars increase the rates of several important reactions. Unburned hydrocarbons can more easily be converted to carbon dioxide and water in the presence of a catalyst. Additionally, carbon monoxide (a harmful gas produced by incomplete combustion of fuel) is further oxidized to carbon dioxide, and... | A: catalyst. |
What do plasmodesmata connect to in the plant cell?
Here are the choices:
A. pores
B. cytoplasms
C. sporozoans
D. nuclei | Plasmodesmata are gaps between plant cells, connecting the cytoplasms of plant cells. | B: cytoplasms. |
What are compounds composed of only two elements called?
Here are the choices:
A. digital compounds
B. kinetic compounds
C. binary compounds
D. symbiotic compounds | Binary compounds are compounds composed of just two elements. The simplest kind of decomposition reaction is when a binary compound decomposes into its elements. Mercury(II) oxide, a red solid, decomposes when heated to produce mercury and oxygen gas. | C: binary compounds. |
What type of gases trap heat in the atmosphere, causing earth to have a moderate temperature?
Here are the choices:
A. ozone gases
B. carbon monoxides
C. greenhouse gases
D. sulfuric gases | Greenhouse gases trap heat in the atmosphere. This is essential so that Earth has a more moderate temperature. Without greenhouse gases, nighttime temperatures would be frigid. Natural greenhouse gases include carbon dioxide, methane, water vapor, and ozone. CFCs and some other man-made compounds are also greenhouse ga... | C: greenhouse gases. |
What system is the brain the control center of?
Here are the choices:
A. fibrous
B. adrenal
C. circulatory
D. nervous | The brain is the control center of the nervous system. It controls virtually all mental and physical processes. | D: nervous. |
Air pollution can cause disease of what system by affecting the health of your lungs?
Here are the choices:
A. excretory
B. digestive
C. respiratory
D. cardiac | Air pollution is another significant cause of respiratory disease. The quality of the air you breathe can affect the health of your lungs. Asthma, heart and lung diseases, allergies, and several types of cancers are all linked to air quality. Air pollution is not just found outdoors; indoor air pollution can also be re... | C: respiratory. |
Why does the body react to a loss of chloride ions?
Here are the choices:
A. increased tricarbonate reabsorption
B. decreased bicarbonate reabsorption
C. decreased tricarbonate reabsorption
D. increased bicarbonate reabsorption | Chloride ions are important in neutralizing positive ion charges in the body. If chloride is lost, the body uses bicarbonate ions in place of the lost chloride ions. Thus, lost chloride results in an increased reabsorption of bicarbonate by the renal system. | D: increased bicarbonate reabsorption. |
The negatively charged electrons are attracted to the positively charged what?
Here are the choices:
A. ion
B. atom
C. nucleus
D. axon | C: nucleus. | |
Most of the gray matter is on the surface of the brain, surrounding what other type of matter?
Here are the choices:
A. blue
B. corrugated
C. white
D. dark matter | C: white. | |
Cooling or evaporation of what from the sea surface makes surface water dense?
Here are the choices:
A. fresh water
B. warm water
C. dirty water
D. salt water | Cooling or evaporation of fresh water from the sea surface makes surface water dense. This causes the surface water to undergo downwelling. | A: fresh water. |
What is the term for reproductive cells, such as sperm and egg?
Here are the choices:
A. nucleus
B. parasites
C. spores
D. gametes | Sexual reproduction combines gametes from two parents. Gametes are reproductive cells, such as sperm and egg. As gametes are produced, the number of chromosomes must be reduced by half. Why? The zygote must contain genetic information from the mother and from the father, so the gametes must contain half of the chromoso... | D: gametes. |
What material is regularly used in human hip and knee implants?
Here are the choices:
A. wood
B. glass
C. metal
D. coal | Metal is regularly used in the human body for hip and knee implants. Most implants need to be replaced over time because, among other things, metal does not bond with bone. Researchers are trying to find better metal coatings that would allow metalto-bone bonding. One challenge is to find a coating that has an expansio... | C: metal. |
What are the most dramatic, sudden, and dangerous types of mass wasting?
Here are the choices:
A. landslides
B. monsoons
C. volcanoes
D. earthquakes | Landslides are the most dramatic, sudden, and dangerous types of mass wasting. Landslides are sudden falls of rock; by contrast, avalanches are sudden falls of snow. | A: landslides. |
What current-carrying long coil of wire acts as a magnet?
Here are the choices:
A. antenna
B. solenoid
C. igniter
D. converter | Magnetic Field Produced by a Current-Carrying Solenoid A solenoid is a long coil of wire (with many turns or loops, as opposed to a flat loop). Because of its shape, the field inside a solenoid can be very uniform, and also very strong. The field just outside the coils is nearly zero. Figure 22.40 shows how the field l... | B: solenoid. |
In combination or synthesis reactions, two chemical species combine to produce a what?
Here are the choices:
A. mixture
B. alloy
C. new compound
D. fusion | In combination or synthesis reactions, two chemical species combine to produce a new compound. The general expression for a combination reaction is:. | C: new compound. |
The core of a star collapses during what event, forming a neutron star?
Here are the choices:
A. gravitational
B. supernova
C. spark
D. blast | The average particle energy needed to observe 19 GeV . (a) What unification of forces is estimated to be 10 is the rest mass in kilograms of a particle that has a rest mass 19 of 10 GeV/c 2 ? (b) How many times the mass of a hydrogen atom is this? 14. The peak intensity of the CMBR occurs at a wavelength of 1.1 mm. (a)... | B: supernova. |
What is the term used for a large body of air of the same temperature and moisture conditions?
Here are the choices:
A. sky mass
B. air mass
C. air pool
D. air group | An air mass is a large body of air that has about the same conditions throughout. For example, an air mass might have cold dry air. Another air mass might have warm moist air. The conditions in an air mass depend on where the air mass formed. | B: air mass. |
The loss of oxygen to the heart muscle causes that part of the tissue to what?
Here are the choices:
A. beat harder
B. die
C. thrive
D. beat erratically | The image below shows the way in which a blocked coronary artery can cause a heart attack. The loss of oxygen to the heart muscle cause that part of the tissue to die. Maybe one day, stem cell therapy will allow for the replacement of the dead cells with new cardiac muscle cells. | B: die. |
What system transports many substances to and from cells throughout the body?
Here are the choices:
A. physiological
B. nutritional
C. circulatory
D. cardiovascular | The cardiovascular system transports many substances to and from cells throughout the body. | D: cardiovascular. |
What consists of two or more elements and forms as a result of a chemical reaction?
Here are the choices:
A. particle
B. protein
C. compound
D. molecule | Living things consist of matter, which can be an element or a compound. A compound consists of two or more elements and forms as a result of a chemical reaction. | C: compound. |
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